Method of and means for producing oscillating currents of high frequency



July 14,1925. 1,545,599 1 P. o. PED-ERSEN METHOD OF AND MEANS FOR PRODUUING OSCILLATING CURRENTS OF HIGH FREQUENCY Filed March 22, 1921 1lllIIlllll WITNESS IN E TOR P 0. Ffoflisfiy ATTORNEYS Patented July 14, 1925.

UNITED STATES PATENT OFFICE.

PEDER OLUF mmnon' or AND MEANS roe raonucme oscrrrerme FREQUENCY.

DENMARK, ASSIGNOR T0 POULSEN Application filed March 22, 1921. Serial No. 454,547.

To all whom it may concern:

Be it known that I, Prone OLUF Penna-'- SEN, a subject of'the King of Denmark, and a resident of Fredericksberg, Denmark, have invented a certainnew and useful Method of and Means for Producing Oscillating Currents of High Frequency, of which the following is aspecification.

The invention relates to a method of and apparatus for producing high frequency currentsuch as is employed in radio signaling. .Heretofore, arc generators forproducing a high frequency currenthave comprised two electrodes between which the arc is formed, an atmosphere containing hydrogen or comparable gas, and means for producing a homogeneous transverse magnetic field. The are body and its craters have been exposed to a magnetic field of substantially uniform density. When the intensity of this field under given conditionshas a cer-' tain critical-value, the percentage which the magnetic field adds to the efficiency of the arc generator has heretofore been considered as the maximum. It has now been de termined, however, that the efficiency of the arc-generator can be further increased by using magnetic fields ofdifferent form.

The cycle of the arc comprises three stages, to wit, striking, burning and extinction. One of the functions of the magnetic fieldis to blow the are out, or, in other words, to produce the necessary high extinc tion voltage at the end of each cycle, but the efficiency of the arc is increased'when the arc voltage is kept low during the burning period. 'With the are operating in a homogeneous transverse magnetic field, its bowing out or traveling out along the electrodes during a cycle will occurat a speed which is gradually increasing from the moment the arc is struck and, consequently, the are resistance and the arc voltage are gradually increased during the cycle. I have determined that the efficiency of the arc will be increased if the arc voltage is maintained at alow value duringthe longer part of the cycle, and this. low voltage. is preferably that at which the arc started its traveling and thennear the point of extinction israpidly increased to the necessary extinction value. g

An object of the. invention, therefore, is to increase the efficiency of the are generator.

magnetic field and during'the LAnother object of the invention is to provlde an improved method radio frequency current.

of producing cunannrs or IHIGH' Another object of the inventionis to pro vide means for maintaining an arc at'ia very low voltage during the major part of a cycle and to rapidly increase the voltage at the end of the cycle to extinguish the arc.

The invention possesses other advantageous features, some'of which, with the foregoing, following description, in full, those forms of invention which Ihave tion in the drawings accompanying and forming part of the present'specification. In said drawings I have shown several forms of apparatus embodying my invention, but it is to be understood that I do not limit myself to such forms, since the invention, as expressed in the claims, may be embodied in other forms.

Referring to said drawings:

where I shall outline the apparatus of-the will be set forth at length in the selected for illustra- Fig. 1 is a diagrammatic representation of one magnet pol'e piece Fig. 4 is atop view of thearrangement,

shown in Fig. 3.

Fig.6 is an end elevation of a" further modified form of ment. p e V Fig. 6 is a top view of the arrangement shown in Fig. 5.

pole-piece in-its ,environ- Fig.7 isaside elevation of a further modified form of pole piece in its environ I ment. 7

Fig. 8 is a top view of'the'arrangement shown inFig. 7. 1

Fig.9 is a diagrammatic representation of an oscillation generating circuit togwhich my'invention, is applicable.

In accordance with my invention, the are is placed in an inhomogeneous transverse magnet-1c field, or fields, ofsuch form, or

forms, that' at. the instant ofi itionthe arc is disposed in a comparatlvely weak I eater portion of its cycle or, period 1s traveling through a comparatively weak magnetic can while toward the end of its cycle or period ;-the arc is exposed to a strong magnetic field of such intensity that the extinguishing voltage is reached just at the right moment and within the shortestspaceof time. In other .words,.the arc :is maintained in the weak magnetic field during thegreater portion of its cycle and moves into the strong magnetic field as the instant of extinction approaches, causing the ,arc ,to operate efiiciently and to "be abruptly extinguished. I have also determined that under certain circumstances, a further advantage maybe obtained by arranging thema gnetic field so that the intensity of the field at the anode is different from that at {the cathode, In the drawings 1 have, shown an anode Anand a cathode K between which the 321.130 is formed in the atmosphere containing hydrogen or its equivalent. The anode is usually formed of copper and is narrower than .the cathode, which is usually formed of carbon. Arranged on opposite sides of the arc gap arepolepieces NandSfbetween which a ,inagnetic field is produced end the pole pieces .arejso formed that an inhomogeneousrnagnetic field is produced. In the construction shown in Fig. 1,.the pole pieces are .cut away, at the bottom to provide somewhat lune-shaped pole faces with the cut.- awayportionof the faces lying ,inline with the arc gap and the {an taceslyingwabovc the arc gap. The. magnetic fieldinthe-arc gap is therefore much weaker 'than directly above thearc .gap,.s thatthe are is'struck in a weak field as it burns and bows upwardly it movesinto the strong ,fieidand is extinguished abruptly at the send of the cycle. 1 i :In Fig. 3 .1 have shownia modified vform of constructionin which sector shaped shoes 3 .are pivotally mounted on the stud ton the end of the pole piece and .the positions .ofgthe shoes maybe varied whil thefa'rc is burning to warythe form of thcfield,

In Fig. 5 I have shown a construction which provides for the inhomogeneous mag-t netic field and at the same time provides for different flux intensities on the anode; and ath d d of h are is formed with two projections tep educ projections hap d the inhomogeneous .fielch and r-the are of different lengthso that the projections .5 which .are op'posed .to the anjede lie fa he apa han' th 'nmie ons 6, which are opposed-,to the cathode, gthus rrducia a stto ger magn ic fie dr thetiers e-cie he are in t ad of pm idans ea 1 ipel p cs wi -W0 le jectime We r le piec s a e e a the r beemployed, as shown in Figs. 7 and 8.

,Qne pair of pole pieces :N TTS are arranged czpesit he nedei d t e t rin N T ate-arranged ne-a s the se h e, f Ih rtiiterence im na netic fi ahetween'the two sides of the arc may be obtained by diflerent wit -h their axes above -the electrodes,

Ea h p le :piece #be'rs otturnsiinthe magnet-windings in other Worde -providing different ampere turns on each pair of poles. The'poles are positioned so that the inhomogeneous magnetic field is produced,.thelfield at the arc gap being weak and the field above'the arc gap being strong.

The are is supplied with current,tfrorn the direct current generator 8 and the windings o'fjthe magnets are connected in series on the ungrounded side of {the are. .Connected to the electrodes [is oscillatory circuit con-. taining the inductance Qandconneoted to the antenna 12. Theotherendgof the circuit is grounded, the earth and the antenna form n capac y in heeir u t ,lclaimr V 1.; The .me-hodnf increasi g th e ficiency Qfim are converter t at i onnected to a load circuit ,to supplyjit with load current, which comprises .alternatively igniting and xtinguishinathear a the .fr e en y otth load. current, influencing the are by transverse magn t ld, causing said (fi d to be substantially stronger at the time of extinctionthan at the time ignition.

,2. Theme Qd f..i ;-.r sthe Qflidawr ofvan re counter that is conn c ed to load circuit to, supply it with load current. wh h Qmpri sa t r a ive igniting a d ingu hing th m ath f equen y o the -c ent, and u j ing a darc ties its p ods of burn ng o tran ers anesnetic .fieldof such characteristics that, has the arc bowsout in these periods, it is subjected ,to ,a magnetic field the intensity of which increases extinction- 1 i A -r q en y os illatims n atcr comprising .a pair of. electrodes between which anoscillatingarc ,inay be formed, and means @for producing; a transverse magnetic field .n a e h le trcde f e fect ng the a e e i ld -n a n c r de ing cf greater intensity than thatnear the other.

. 4. .A- radio t equency constant wav cs' i lation .generatorcomprisin a pair. at electrodes .betweenawhich. an .oscillating'arc nay h ormed, and meansip apr ducina homogeneous transverse.,magnet-ic field af ect ng the arc, .the field :beingof substantially -greater intensity near that region ,o-f.the, ,electrodes wherethe are ishroken.

In I Q i s i n r ar s m st er producing constant wave oscillations, a pair of electrodes between which an arc may he ,,or rn.ed,,.a load .circuit supplied with current trom .thearc at )the frequency :ojf. the ignitipn f om:th meoiigniticn to thatoj and extinction of the are, and means fersubof the field affecting it increases materially up to the point of extinction.

6. The method of operating a constant wave radio frequency arc converter, that is connected to a load circuit to supply it with load current which comprises causing the arc to be alternately ignited and extinguished at the frequency of the load current, while subjected to a transverse magnetic field, and subjecting the arc to an abruptly increased intensity of the field near the position of extinction.

7. In a radio frequency arc converter for producing constant wave oscillations, a pair of electrodes between which an arc may be formed, a load circuit supplied with current from the arc at the frequency of the ignition and extinction of the arc, and means for subjecting the arc to a transverse magnetic field, the field being such that as the arc bows to its extinction point, the intensity abruptly increases.

8. In a radio frequency are converter for producing constant wave oscillations, a pair of electrodes between which the arc may be formed, a load circuit supplied with oscillating current from the arc, and means for extinguishing the are periodically at the rate of the frequency of the load current, comprising means for producing a transverse magnetic field of non-uniform intensity, the intensity being weakest in the field where the arc is ignited, and strongest in the field where the arc is extinguished.

9. A constant wave arc generator for the generation of electrical oscillations of high frequency, comprising two electrodes between which an arc is formed, a load circuit supplied with current from the are at the frequency of the ignition and extinction oftween which an arc is formed, a load circuit supplied with current from the arc at the frequency of the ignition and extinction of the arc, and magnetic pole pieces arranged on opposite sides of the arc, the pole faces being shaped to produce an inhomogeneous magnetic field across the which the arc travels.

11. A constant wave arc generator for the generation of electrical oscillations of high frequency, comprising two electrodes between which an arc is formed, a load circuit supplied with current from the are at the frequency of the ignition and extinction of the arc, and means for subjecting the arc to a transverse magnetic field of increasing intensity outward from the arc gap.

12. An arc generator for the'generation of electrical oscillations of high frequency,

space through comprising two electrodes between which an arc is formed, magnetic pole pieces arranged on opposite sides of the arc and adjustable shoes on said pole pieces.

In testimony whereof, I have hereunto set may hand.

PEDER OLUF PEDERSEN. 

